In the following text, laser head means not only a laser amplifier comprising simply an active material and excitation means for this material but also covers a laser generator futher having an optical resonant cavity in which the active material is disposed.
Industrial laser heads cooled by a liquid comprise, in general, a chamber filled with a liquid which is often constituted by a mixture of water and anti-freeze. The active material and the flash lamp of the laser head are immersed in this liquid. The sealing of the chamber should prevent all leakage of liquid during transfer and during the operation of the device.
Despite all the precautions taken to prevent air from being dissolved in the liquid, it is observed that gas bubbles are formed within the liquid during operation. There results therefore, an overpressure in the chamber which can cause, after a time, leakages at the seal rings and which disturbs the cooling of the active laser material. When the device comprises a liquid flow pump, these gas bubbles can also unprime the pump.
Preferred embodiments of the present invention mitigate these disadvantages and produce a device for liquid cooling a laser head, in which the gas bubbles which form during operation of the laser are removed without causing leakage of liquid.